System Bits: March 6

Printed graphene biosensors
According to researchers at the Fraunhofer Institute for Biomedical Engineering IBMT in St. Ingbert (in Germany’s Saarland region), cell-based biosensors can simulate the effect of various substances, such as drugs, on the human body in the laboratory but depending on the measuring principle, producing them can be expensive. As such, they aren’t used very often. Further, cost factors for sensors that perform measurements electrically include the expensive electrode material and complex production.

Endless film with printed biosensors: Fraunhofer has developed a convenient roll-to-roll process.
Source: Fraunhofer IBMT

Now, however, Fraunhofer scientists are producing biosensors with graphene electrodes cheaply and simply in roll-to-roll printing. A system prototype for mass production has been completed as well, they reported.

Specifically, the researchers explained that cell-based biosensors measure changes in cell cultures via electrical signals, which is done by means of electrodes mounted inside a Petri dish, for example. If added viruses destroy a continuous cell layer on the electrodes, the electrical resistance measured between the electrodes is reduced, and in this way, the effect of vaccines or drugs can be tested such that the more effective the active ingredient is, the smaller the number of cells that are destroyed by the viruses and the lower the measured resistance change will be. Toxicity tests can also be performed, such as on cosmetic products, and can function according to the same principle and may replace animal experiments in the future. Another advantage the researchers reported is that if biosensors are linked to an evaluation unit, measurements can be continuous and automated.

These types of biosensors are expensive and complex. Typically, the electrodes are made of a biocompatible and electrically conductive material, such as gold or platinum. Also, the production of microelectrodes requires a complicated lithographic process. As a result, laboratories often do not buy these biosensors because of the high costs, and examination of the cell cultures usually continues to be performed manually under a microscope.

But now, as an alternative to precious metals, graphene can be used as a material for the electrodes. The advantages of the carbon material is that it is electrically conductive, biocompatible and, if in the form of an ink, can be printed on surfaces.

The researchers have made use of such a graphene ink. They have teamed with industry partners in the M-era.Net project BIOGRAPHY — funded by the German Federal Ministry of Education and Research (BMBF) — to develop a printing process which makes it possible to produce large numbers of graphene biosensors in a cost-effective roll-to-roll process.

Dr. Thomas Velten, Head of the Biomedical Microsystems Department at IBMT and Project Manager of BIOGRAPHY, said the system prototype can print about 400 biosensors per minute on a continuous foil.

Read further details here.

The team expects to be able to offer the industry a universal technology platform in no later than a year.

Trapped-ion quantum computer building blocks
Oxford University researchers have set a new speed record for the ‘logic gates’ that form the building blocks of quantum computing that could transform the way we process information.

They reminded that quantum computers function according to the laws of quantum physics, and have the potential to dwarf the processing power of today’s classical computers. The Oxford team is using a trapped-ion technique to develop its computer, in which logic gates place two charged atoms, containing information in the form of quantum bits, or qubits, in a state of quantum entanglement.

Dr Chris Ballance and Vera Schäfer with ion-trap apparatus in one of Oxford’s quantum technology laboratories.
Source: Oxford University

Einstein described this entanglement as ‘spooky,’ which is at the heart of quantum technology. It means that the properties of the two atoms stay linked, even when they are separated by great distances.

The research builds on previous work in which the team, led by Professor David Lucas and Professor Andrew Steane of Oxford’s Department of Physics, achieved a world record for the precision of the logic gate, reaching the demanding accuracy set by theoretical models of quantum computing.

According to Professor Lucas, “Trapped-ion qubits have long been the touchstone for precision in the world of quantum computing, and also have the nice feature that they interface naturally to photons for networking applications. But one drawback was that the basic entangling operations were always rather slow. In our latest experiment, we were able to generate entanglement in times as short as 480 nanoseconds, demonstrating that the logic speed doesn’t have to be limited by the natural timescale of the ‘pendulum/ motion of the ions.”

Self-aware AI ocean predator
University of Illinois researchers report in a new paper on an AI cyberslug they created that the simulation validates experimental data and provides a basic module on which complexity in economic, cognitive, and social behaviors could be built. In other words, this could be the start of increasingly intelligent AI creatures.

Cyberslug, depicted in this cartoon as a cyborg, is an artificially intelligent creature.

Source: University of Illinois

The team said their artificially intelligent ocean predator behaves a lot like the original flesh-and-blood organism on which it was modeled, and the virtual creature, “Cyberslug,” reacts to food and responds to members of its own kind much like the actual animal, the sea slug Pleurobranchaea californica, does.
Interestingly, unlike most other AI entities, Cyberslug has a simple self-awareness, said University of Illinois molecular and integrative physiology professor Rhanor Gillette, who led the work with software engineer Mikhail Voloshin. This means it relates its motivation and memories to its perception of the external world, and it reacts to information on the basis of how that information makes it feel.

In previous work, Gillette and his colleagues worked out the brain circuitry that allows sea slugs to operate in the wild, “down to individual neurons,” he said. To test the accuracy of their models, the researchers experimented with simple computer simulations. One of the first circuitry boards Voloshin built to represent the sea slug brain was housed in a plastic foam food takeout container.

But the new model uses more sophisticated algorithms to simulate Cyberslug’s competing goals and decision-making, Gillette said. Over time it learns what is good – and not so good – to bite. Just like P. californica, the more it eats, the more satiated it becomes and the more likely it is to avoid other creatures. But as hunger returns, Cyberslug becomes a less picky eater.

The researchers believe, “the sea slug is a good model of the core ancient circuitry that is still there in our brains that is supporting all the higher cognitive qualities. Now we have a model that’s probably very much like the primitive ancestral brain. The next step is to add more circuitry to get enhanced sociality and cognition.”